Letoff mechanism for looms



Feb. 20, 1945. s -J. GEDDINGS LET-*OFF MECHANISM FOR LOOMS Filed June l5, 1944 2 Sheets-Sheet l www S. J. GEDDINGS LET-OFF MECHANISM FOR LOOMS Feb. 2G, 19.45.

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,4 770A Ne' y Perentd Feb. 2o, 1945 UNITED STATES PATENT oFFlcE 2,369,889 LETOFF MECHANISM FOR LOOMS Saint Julian Geddings, West Columbia, S. C. Application June 15, 1944, Serial No. 540,392

9 Claims.

My invention relates. to let-01T mechanism for looms. i

The conventional let-off mechanism for looms comprises a pawl and ratchet means to turn the warp-beam intermittently to pay out the warp. The' extent of the turning movement of the ratchet. upon each stroke of the pawl is regulated by the tension of the warp and the diameter of the yarn upon the warp-beam. `The warp-beam has a large gear, engaging a pinion which vis turned at a reduced speed by the pawl and ratchet means. The warp-beam is mounted upon the loom frame near its rear end and adjacent to the pawl and ratchet means. The warp from the Warp-beam engages the whip-roll of the tension means and an arm engages the periphery of the yarn mass wound upon the warp-beam. The tension means and the arm regulate the extent of turning movement of the warp-beam upon each feed stroke of the pawl, by varying the starting point of the pawl, according to the warp tension and the diameter of the yarn mass upon the warp-beam. The let-off mechanism for looms thus far-described are shown in patents,r

Nos. 647,815; 744,941; and 981,944.

Due to the arrangementr of the warp-beam upon and within the frame of the loom, the diameter of the warp-beam is limited, for it would interfere with the operation of parts of the loom. The average warp-beam has a diameter of about A20 inches.

By the use of a warp-beam having a larger diameter, much time and work can be saved in the operation of a loom, as the warp beam would not have to be changed as frequently.

In accordance with my invention, I use a warpbeam of considerably larger diameter than the conventional Warp-beam, and drive the larger warp-beam from the conventional let-off mechanism. In accordance with my invention, a stand -is arranged at the rear end of the loom frame and preferably connected therewith, and a warp beam of larger diameter, such as 32 inches is rotatably mounted -upon the stand. This warpbeam is equipped with a large beam-gear and I interpose gearing, preferably embodying two meshing pinions, between the beam-gear and the driving pinion operated bythe pawl and ratchet means of the letoff mechanism. By this means, the large warp-beam is driven in the same direction and at the same speed, as is required with the ordinary smaller warp-beam mounted upon the loom frame. The same pawl and ratchet means is employed to rotate the driving pinion, and this pawl and ratchet means has its actionl controlled by the tension of the warp and the beam.- I also provide an inclined cross head which supports the intermediate pinions, and the arrangement is .such that when excessive strains occur, and there is a slight yielding action of the inclined cross head, the pinions will tend to move from the beam-gear and the driving pinion, thus eliminating any possibility of the engaging gears or pinions binding or stripping. Further, the arrangement permits of the inner intermediate pinion being brought into mesh with the driving pinion, by a downward movement of the bracket, when it is placed in engagement with the side frame of the loom. Further, the intermediate pinionsvl are much smaller in diameter than the driving pinion ordinarily employed, thus increasing the gearl ratio between the beam gear and the intermediate pinions, whereby these intermediate pinions serve to some extent as a brake, whereby the usual braking element of the let-oil` mechanism is suiiicient for controlling the action of the warp beam ofthe increased diameter.

My invention may be applied to a loom equipped with a standard Roper let-oil mechanism, as shown in patents, 647,815; 744,941; and 981,944, lwithout materially altering the construction 0f the loom or the let-off mechanism.

In accompanying drawings forming a part of this application and in which like numerals are employed* to designate like parts throughout the same, i

Figure 1 is a side elevation of a loom embodying my invention,

Figure 2 is ap1an view of the same, parts broken away and parts omitted', showing my large warp-beam mounted exteriorly of loom frame,

Figure 3 is a transverse section taken on line 3-3 of Figure 2, and

Figure 4 is a perspective view of a bracket which supports the intermediate pinions.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral I0 designates the sides of a loom frame. This loom frame is equipped with let-ofi mechanism including pawl and` raty roll W, and is also controlled by an arm E.

The p'awl and ratchet means turns a driving pinion B2. These parts are identical with the corresponding parts shown in the patents to C. F.

Roper, 744,941 and A. E. Rhoades, 981,944. I have used the same reference characters as employed in said patents for the sake of clearness.

Arranged at the rear end of the sides I8 of the loom frame is a stand including inverted L-shaped brackets II. These brackets are vertically arranged and have their horizontal arms I2 rigidly attached to the rear ends of the sides IIJ by bolts I3. The brackets II have bearings I4.

The numeral I5 designates my large warpbeam, having ends I6, which may be 32 inches in diameter. The warp-beam I5 is tubular for the passage ci a shaft I1 rotatable within the bearings I4. The ends I6 have beam-gears I8 rigidly secured thereto. It is thus seen that the warp-beam is supported at the rear end of the loom frame entirely exteriorly of the frame and that therefore a much larger warp-beam can be used.

The numeral I9 designates a vertical bracket having a base 28, to be rigidly clamped to a transverse beam 2I of the loom frame, by bolts 22. The vertical bracket has a vertical extension 23 at its upper end, rigidly secured to the side I 0, by a bolt 24. The vertical .bracket I8 has a lateral and inwardly projecting extension 25, carrying a crosshead 26, preferably inclined at an angle of about 4 degrees from the horizontal. The crosshead 26 carries spindles or shafts 21, horizontally arranged, and having intermediate pinions 28 rotatable thereon. The intermediate pinions are in permanent mesh with each other. The rear intermediate 'pinion 28 is arranged to mesh with the tbeam gear I8 while the front pinion 28 meshes with the driving pinion B2. It is thus seen that the intermediate pinions 28 will cause the beam gear i8 to be driven byV the driving pinion B2,

in the same direction and at the same speed as would lbe the case if the beam gear I8 directly engaged the driving pinion B2. The crosshead 26 is inclined, 'as stated, and extends downwardly towards the Ibeam gear I8 and upwardly toward the driving pinion B2. As a result of this, the intermediate pinion 28 which engages the beam gear I8, has its center below the center of the warp beam, and the other intermediatepinion 28 has its center above the center of the operating pinion B2. When an excessive load or force is applied to the adjacent intermediate pinion 28 by the beam gear I8, the cross-head 26 will yield slightly, since it is practically impossible to have the parts of a loom completely rigid so that they will not yield slightly during operation. The pinion 28 will, therefore move downwardly and from the beam gear I 8,'the crosshead 26 turning slightly upon the arm 25, thereby eliminating any possible binding action between the pinion 28 and beam gear I8 or the stripping of the teeth of these elements, while at the same time the other pinion 28 will move slightly from the driving pinion B, thereby eliminating any possibility of binding action between these elements or the stripping of the teeth. Of course this relative movement is slight so that the pinions or gears remain permanently in mesh. In applying the bracket to the side frame of the loom, the bracket may be arranged in contact with the side frame with the pinion 28 near and above the driving pinion B2. The bracket may then be lowered so that its base 20 will engage the transverse beam 2I, and the pinion 28 will tlen be brought into mesh with the driving pinion B The warp 28 passes from the warp-beam I5 over the whip-roll, and the arm E' has a horizontal extension 38, which contacts with the periphery 3| of the yarn Wound upon the warpbeam. Hence the action of the let-oit mechanism is controlled by the tension of the warp and by the diameter of the yarn 3I wound upon the Warp-beam, as described in connection with Patent 744,941. The lever E' is identical with the same lever in Patent 744,941 except that in applicants device the lever E has the horizontal extension 38 so that it may engage the periphery 3l of the yarn wound upon the warp beam.

In view of theforegoing description it will thus be seen that during the operation of the loom, and as the cloth is being woven, as is well known, the warp will be paid outby the action of the let-off mechanism and such action is controlled by the tension of the warp and the diameter of the yarn wound upon the warp-beam.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention what I claim is:

1. In a loom apparatus, a loom frame, auxiliary supportin-g meyans arranged near one end of the loom frame, a large warp-'beam rotatably mounted upon the auxiliary supporting means, a beam gear secured to the warp beam, let-off mechanism mounted upon the loom frame and having its action controlled by the tension of the Warp and the diameter of the yarn wound upon the warp beam, a driving pinion turned by the let-oli' mechanism, and gearing including intermediate pinions, one intermediate pinion engaging the beam gear and the other intermediate pinion engaging the driving pinion.

2. In a loom apparatus, a loom frame, auxiliary supporting means arranged near one end of the loom frame, a large warp-beam rotatably mounted upon the auxiliary supporting means, a beamgear secured to the warp-beam, let-off mechanism mounted upon the loom frame and having its action controlled :by the tension of the warp and the diameter of the yarn Wound upon the warp-beam, a driving pinion turned by the letoff mechanism, a bracket mounted upon the loom frame, and intermediate pinions carried |by the bracket, the intermediate pinions meshing and one intermediate pinion meshing with the beamgear and the other intermediate pinion meshing with the driving pinion.

3. In a loom apparatus, a frame, auxiliary supporting means arranged near one end of the loom frame, a warp-beam rotatably mounted upon the auxiliary supporting means, a beam-gear secured to the Warp-beam, let-olf mechanism mounted upon the loom frame and having its action controlled by the tension of the warp and the diameter of the yarn wound upon the warpbeam, a driving pinion turned by the let-ofi mechanism, an upstanding bracket having a base at its bottom and an extension at its top and a laterally projecting arm and a crosshead carried by the arm, means to clamp the base and extension to the loom frame, and intermediate pinions mounted upon the crosshead, the intermediate pinions meshing with each other and one intermediate pinion meshing with the beamgear and the other intermediate pinion meshing with the driving pinion, the bracket and intermediate pinionsV being removable as a unit.

4. In a loom apparatus, a loom frame, auxiliary supporting means arranged near one end of the loom frame. a large warp-beam rotatably mounted upon the auxiliary supporting means, a beam gear secured to the warp-beam, let-ofi mechanism mounted upon the loom frame and having its action controlled by the tension of the warp and the diameter ofthe yarn wound upon the warpbeam, a driving pinion turned by the let-off mechanism, and intermediate pinions which mesh with each other and engage the driving pinion and beam gear.

5. In loom apparatus, a loom frame, auxiliary supporting means arranged near one end of the loom frame, a large warp-beam rotatably mounted upon the auxiliary supporting means, a beam gear secured to the warp-beam, let-olf mechanism mounted upon the loom frame and having its action controlled by the tension of the warp and the diameter of the yarn wound upon the warp-beam. a driving pinion turned by the let-of! mechanism, intermediate pinions arranged between the driving pinion and beam gear, one

intermediate pinion engaging the driving pinion and the other intermediate pinion engaging the beam gear, and yielding means supporting the intermediate pinions, the yielding means permitting the intermediate pinion engaging the beam gear to move from the -beam gear to prevent locking. A

6. In loom apparatus, a loom frame, auxiliary supporting means arranged near one end of the loom frame", a large warp-beam rotatably mounted upon the auxiliary supporting means, a beam gear secured to the warp-beam, let-off mechanism mounted upon the loom frame and having its action controlled by the tension of the Warp and the diameter of the yarn wound upon the warp-beam, a driving pinion turned by the let-olf mechanism, intermediate pinions arranged between lthe driving pinion and beam gear, oneintermediate pinion engaging the driving pinion and the other intermediate pinion engaging the beam gear, yielding means for supporting the intermediate pinions with their axes of rotation at different elevations, the intermediate pinion engaging the beam-gear having its axis of rotation- 7. In loom apparatus, a loom frame, auxiliary supporting means arranged near one end of the loom frame, a large warp-beam rotatably mounted upon the auxiliary supporting means,

a beam gear secured to the Warp-beam, let-01T mechanism mounted upon the loom frame and having its actioncontroiled by the tension of the Warp and the diameter of the yarn Wound upon the Warp-beam, a driving pinion turned by the let-off mechanism, intermediate pinions arranged between the driving pinion and beam gear, one intermediate pinion engaging the driving pinion and the other intermediate pinion engaging the beam gear, the intermediate pinions engaging each other and being of much smaller diameter than the driving pinion and thereby serving as a brake against over-running action of the warpbeam.

8. An attachment for use in connection with a loom including a frame, let-off mechanism mounted upon the frame and having its action controlled by the tension of the warp and the diameter of the yarn wound upon the warp-beam, said mechanism including an elongated arm, and a driving pinion turned by the let-off mechanism; said attachment comprising auxiliary supporting means arranged near one end of the loom, a large warp-beam rotatably mounted upon the auxiliary supporting means, a beam gear secured to the Warp-beam, and gearing including intermediate pinions, one'intermediate pinion engaging the driving pinion and the other intermediate pinion engaging the beam gear, the elongated arm engaging the Warp wound upon the warp-beam.

9. An attachment for use in connection with a loom including a frame, let-oi mechanism Amounted upon the frame and having its action controlled by the tension of the warp and the diameter of the yarn wound upon the warp-beam, said let-off mechanism including an elongated arm; said attachment comprising auxiliary supporting means arranged near one end of the loom frame, a large warp-beam rotatably mounted upon the auxiliary supporting means, and gearing connecting the let-off mechanism andthe warp-beam, the elongated arm engaging the Warp l wound upon the warp-beam. 

